Safe number comparison in Windows batch file

Question

I know that when comparing stuff for equality in a batch file it\'s common to enclose both sides in quotes, like

IF \"%myvar% NEQ \"0\" 

Bu

Answer 1

Answering the call to nitpick

Mofi has been requesting I write my own solution here, that is "shorter" as I pointed out to him the way he wrote his code using & instead of ( followed by a command then a carriage return and another command, or `( followed by a carriage return, followed by another command followed by a carriage return followed by another command) sets a precedent which makes this a hard task to agree on.

I also did not think this was the POINT of providing the answers perse, I mean I used to, but when changes are minor, and mainly fixing logic, or offering a minorly different solution, is that really a big difference? Does that really warrant being a separate answer?

That said, I don't see a better way without editing his response.. but this still leaves unresolved questions on what is being judged shorter.

Unfortunately as well, in discussing with Mofi he has edited his answer to one that can result in invalid choices.

While I have pointed this out, and I'm sure this was just a minor oversite on his part, I feel like not posting the code here has contributed to him actively deteriorating the quality of his question, which is always a possible outcome when nitpicking.

while Mofi was the driving force in that activity, I don't like the effect it's had on him as I was trying to avoid exactly this effect on my code by not getting into it, so I have decided to post the code comparison to bring some closure for them.

Please not, I will post his original code (the most recent one that did not use the erroneous method), and then refactored to how I would write it, and I will post my Original code, and then refactored to how I believe he would write it (may not be in that order but I will call out each)

So below is the result

Mofi Original:

This is hard to say if you should count every line, there are some instances where & is used to queue up commands and the IFS never use Parenthesis which I wouldn't generally do.

@echo off
set "MinValue=0"
set "MaxValue=20000"

:PromptUser
rem Undefine environment variable MyVar in case of being already defined by chance.
set "MyVar="
rem Prompt user for a positive number in range %MinValue% to %MaxValue%.
set /P "MyVar=Enter number [%MinValue%,%MaxValue%]: "

if not defined MyVar goto PromptUser
setlocal EnableDelayedExpansion
set /A "Number=MyVar" 2>nul
if not "!Number!" == "!MyVar!" endlocal & goto PromptUser
endlocal
if %MyVar% GTR %MaxValue% goto PromptUser
if %MyVar% LSS %MinValue% goto PromptUser

rem Output value of environment variable MyVar for visual verification.
set MyVar
pause

My Code Refactored to Mofi's Form

@ECHO OFF
SETLOCAL EnableDelayedExpansion
SET /A "_Min=-1","_Max=20000"
:Menu
  CLS
  SET "_Input="
  REM Prompt user for a positive number in range %_Min% to %_Max%.
  SET /P "_Input=Enter number [%_Min%,%_Max%]: "
  SET /A "_Tmp=%_input%" && if /I "!_input!" EQU "!_Tmp!" if !_Input! GEQ %_Min% if !_Input! LEQ %_Max% SET _Input & pause & GOTO :EOF 
GOTO :Menu

Mofi's Code Refactored

Mofi's above code Refactored to my more compacted form Where ( have the first command follow except when used on an IF statement, and ) follow the last command. This also makes the entire portion that really does the validation EASY to discern, it is only the portion within the :PromtUser function, not counting REM lines or blank lines this is 13 lines of code.

@(SETLOCAL
  echo off
  SET /A "MinValue=0","MaxValue=20000")

CALL :Main

( ENDLOCAL
  EXIT /B )

:Main
  CALL :PromptUser MyVar
  REM Output value of environment variable MyVar for visual verIFication.
  SET MyVar
  PAUSE
GOTO :EOF


:PromptUser
  SET "MyVar="
  rem Prompt user for a positive number in range %MinValue% to %MaxValue%.
  SET /P "MyVar=Enter number [%MinValue%,%MaxValue%]: "
  
  IF NOT DEFINED MyVar GOTO :PromptUser
  Setlocal EnableDelayedExpansion
  SET /A "Number=MyVar" 2>nul
  
  IF not "!Number!" == "!MyVar!" (
    Endlocal
    GOTO :PromptUser  )
  Endlocal
  IF %MyVar% GTR %MaxValue% (
    GOTO :PromptUser  )
  IF %MyVar% LSS %MinValue% (
    GOTO :PromptUser )
GOTO :EOF

My Code in My Compact Form

To compare here is my code also in the same compact form I refactored Mofi's code to above. Again, only the lines inside of the function itself are "doing the heavy lifting" here and need compare. I did forget that when I worked on my code originally I was trying to match Mofi's form, and it allowed me an extra nicety in keeping my && ( in the following line or all as a single line. So I will post two varients

@(SETLOCAL ENABLEDELAYEDEXPANSION
  ECHO OFF
  SET /A "_Min=-1","_Max=20000" )

CALL :Main

( ENDLOCAL
  EXIT /B )

:Main
  CALL :Menu _input
  REM Output value of environment variable _input for visual verIFication.
  SET _input
  PAUSE
GOTO :EOF


:Menu
  CLS
  SET "_input="
  REM Prompt user for a positive number in range %_Min% to %_Max%. Store it in "_input"
  SET /P "_Input=Enter number [%_Min%,%_Max%]: "
  SET /A "_Tmp=%_input%" && (
    IF /I "!_input!" EQU "!_Tmp!" IF !_Input! GEQ %_Min% IF !_Input! LEQ %_Max% GOTO :EOF )
GOTO :Menu

My Code in My Compact Form 2

@(SETLOCAL ENABLEDELAYEDEXPANSION
  ECHO OFF
  SET /A "_Min=-1","_Max=20000" )

CALL :Main

( ENDLOCAL
  EXIT /B )

:Main
  CALL :Menu
  REM Output value of environment variable _input for visual verification.
  SET _input
  PAUSE
GOTO :EOF


:Menu
  CLS
  SET "_input="
  REM Prompt user for a positive number in range %_Min% to %_Max%. Store it in "_input"
  SET /P "_Input=Enter number [%_Min%,%_Max%]: "
  SET /A "_Tmp=%_input%" || GOTO :Menu 
  IF /I "!_input!" EQU "!_Tmp!" (
    IF !_Input! GEQ %_Min% (
      IF !_Input! LEQ %_Max% (
        GOTO :EOF ) ) )
GOTO :Menu